Conventional household power planning typically involves arranging one or more wall sockets on one or more walls in a room, a switch on a wall close to a door of the room, and a switchable socket electrically connected to the switch. The wall sockets constantly provide mains electricity. The switchable socket is usually inserted with an electric device, such as a lighting fixture. The switch is operable to switch the switchable socket between a conductive state to output mains electricity and a non-conductive state to not output mains electricity, so that it is convenient to turn on or turn off the electric device (e.g., a lighting fixture) by operating the switch at the door of the room.
Rearrangement of the electric device in the room is limited to the position of the switchable socket since the switchable socket is fixed at a specific position on the wall. Though an extension cord can be employed to electrically connect the electric device to the switchable socket, the extension cord may result in a relatively messy appearance.